Transfer Characteristic of Schmitt Trigger
There are two types of Schmitt Trigger:
- Non-Inverting Schmitt Trigger
- Inverting Schmitt Trigger
Non-Inverting Schmitt Trigger
When the input signal is applied at the non-inverting (+ve terminal) terminal and ground is connected to the inverting (-ve terminal) terminal of of Op-Amp, it is called Non-Inverting Schmitt Trigger.
The figure given below shows the transfer characteristics of Non-Inverting Schmitt Trigger. The curve shown is called the hysteresis curve. Let’s study the graph in detail.
The number ‘1’ marked on the above graph shows that the output voltage will remain low until Vin crosses the VUT. When the input signal crosses the upper threshold voltage, the output voltage becomes HIGH.
The number ‘2’ marked on the above graph shows that if the input signal starts decreasing, Vout will remain high until Vin crosses the lower threshold voltage. When the input signal crosses the VLT, the output voltage becomes LOW.
Hence, it will form a hysteresis curve that keeps on working continuously.
Inverting Schmitt Trigger
When the input signal is applied at the inverting terminal (-ve terminal) and ground is connected to the non-inverting (+ve terminal) terminal of of Op-Amp, it is called Inverting Schmitt Trigger.
The figure given below shows the transfer characteristics of Inverting Schmitt Trigger. The curve shown is called the hysteresis curve. Let’s study the graph in detail.
The number ‘1’ marked on the above graph shows that when Vin < VUT, the output signal remains HIGH.
The number ‘2’ marked on the above graph shows that when Vin> VUT, the output voltage will become LOW.
NOTE: The working of Inverting Schmitt Trigger is opposite of Non-Inverting Schmitt Trigger.
Hence, it will form a hysteresis curve that keeps on working continuously.
Schmitt Trigger
We use Schmitt Triggers in digital electronics. It is used for rejecting the noise from the input signals by using the hysteresis curve. To provide accurate and more stable results, it uses two threshold voltages i.e., upper threshold voltage (VUT) and lower threshold voltage (VLT). It is mainly used in signal conditioning applications to remove noise from signals which is used in digital circuits, particularly mechanical contact bounce in switches. In this article, we will learn more about Schmitt Trigger, its working, and its applications.
Table of Content
- What is Schmitt Trigger?
- Working
- Transfer Characteristics
- Types
- Uses
- Schmitt Trigger Vs Comparator
- Advantages and Disadvantages
- Applications